Carl Jung was a Swiss psychiatrist and an early leader in the psychoanalytic movement, which he left to found analytical psychology. Heir-apparent to Sigmund Freud, Jung served as the first president of the International Psychoanalytic Association. Their split resulted from the movement’s increasing dogmatism and Jung’s insistence on a broader conception of the libido (in Freud, sexual energy) advanced in his Psychology of the Unconscious (1912). Further, in addition to a personal unconscious, Jung postulated a collective unconscious in Two Essays on Analytical Psychology (1917), made up of inherited archetypes that emerge into consciousness as symbol and complex. Jung’s therapeutic goal was individuation, in which both the collective and personal unconscious are integrated into the individual’s conscious conception of self. Unlike Freud, Jung considered religion to be compatible with psychology as a potential support for individuation. In addition to works on the occult, alchemy, and the Bible, Jung wrote prefaces to the I Ching, The Tibetan Book of the Dead, and D.T. Suzuki’s An Introduction to Zen Buddhism. Jung’s influence spread significantly after World War II, popularized by Joseph Campbell and adapted to literary criticism by Northrop Frye. Jung’s work on psychological types would become the basis for the Myers–Briggs Type Indicator.